I refused to buy Dark Souls for years based on claims of a broken, unplayable port. Then I bought it and sure, the port was broken AF but it was still the best videogame experience I've had in my entire life.
I agree with you that it's definitely one of the best videogame experience to be had in one's entire life, but it still doesn't excuse the fact that it's an utterly broken, unplayable port. At least, if you have experienced much better port (Dark Souls 2 SofTS for example), I'm pretty sure no sane mind would ever be able to stand DaS: PtDE without DSFix.
EDIT: Oh and as for the original point of how useful game scores on Epic would be?
Except, in the context of comparing Epic and Steam, Steam doesn't even have 'game scores' on its game reviews. People might be putting their own scores on their reviews itself, but what Steam does is just a simple Recommended/Not Recommended verdict.
Look, the point is, at least in general usefulness reviews is the most direct way of knowing if a game is broken and,
most importantly, how long time has passed since the game's release, brokenness found, devs promises, and if the game is ever fixed at all. The most prominent example I can give you in recent times is Insomnia: The Ark. You should go to the codex thread and see it for yourself. While you and I have the luxury of checking the Codex regularly, and thus able to keep tabs on crucial information like this most of the time, your average joe doesn't really know or perhaps don't even care about looking up about this stuff online other than, you guess it, Steam reviews (and additionally, game's forum itself on Steam). And what do we know, the general sentiment as can be seen observed in Steam reviews and discussion for the aforementioned game echoed that of the Codex's.
And as Rahdulan pointed out, it's also important to know if the reviewers background is more 'in-line' with your general taste. This is simple enough in the Codex, and also on Steam with a single click on a user's account (if it's not private).
Delving into a new genre is probably more difficult, but researching on Google is one way to start, or if there exist any other forums out there like Codex, but for other genres, you ask around there instead.
I hope everybody in this thread understands EVERY SINGLE GAME on EGS would have a "Terribru!1!!1" score, including the non-exclusives? Nobody has any illusions about that right?
I think you're the one who has illusions here.